MOTORISTS whose vehicles have tinted windscreens are being given three weeks to see the light -- or face prosecution.

Police in the Eastern Division, covering Blackburn, Darwen, Hyndburn and the Ribble Valley, made the warning after buying 'Tintman', a £500 piece of equipment that measures the percentage of sun which is allowed through glass.

A European Directive laid down in the 1980s states that the windscreen and front side windows must let more than 75 per cent of light through.

That law has hardly been used, but officers have decided to invoke it on a regular basis after becoming concerned about the growing number of dark tints seen on the road.

They believe the windscreens are a danger because they reduce the drivers' visibility, especially at night.

Officers also struggle to identify people in cars with dark tints, so suspects could pass them by.

Police have decided to enforce the directive from April 27.

Until then, officers from the road policing unit will mount checkpoints, test Tintman on suspect windscreens and advise motorists they need replacing.

After this period, offenders will be given a deadline to rectify the problem or face prosecution and heavy fines.

The punishment will not result in licence penalty points and is seen as a last resort.

Sgt Keith Jackson said: "We have no objections to tinted rear or back side windows. For the windscreen and side windows it is the safety aspect at junctions.

"Most sun-glasses let 25 per cent of light through and you wouldn't wear those at night."

The road policing unit at Accrington police station is staging an open-day on April 26 between 10am and 2pm for people to bring their cars for a Tintman test.

Turnkey Instruments in Northwich is a specialist electronics manufacturer and supplier which has also sold 'Tintman' to other police forces and to car dealerships.